This invention relates generally to detecting diseases of the breast. Furthermore, the invention also relates to reagents and methods for detecting diseases of the breast. More particularly, the present invention relates to reagents such as polypeptide sequences, as well as methods which utilize these sequences. The polypeptide sequences are useful for detecting, diagnosing, staging, monitoring, prognosticating, in vivo imaging, preventing or treating, or determining predisposition to diseases or conditions of the breast, such as breast cancer.
Breast cancer is the most common form of cancer occurring in females in the U.S. The incidence of breast cancers in the United States is projected to be 180,300 cases diagnosed and 43,900 breast cancer-related deaths to occur during 1998 (American Cancer Society statistics). Worldwide, the incidence of breast cancer increased from 700,000 in 1985 to about 900,000 in 1990. G. N. Hortobagyi et al., CA Cancer J Clin 45:199-226 (1995).
Procedures used for detecting, diagnosing, staging, monitoring, prognosticating, in vivo imaging, preventing or treating, or determining predisposition to diseases or conditions of the breast, such as breast cancer, are of critical importance to the outcome of the patient. For example, patients diagnosed with early breast cancer have greater than a 90% five-year relative survival rate as compared to a survival rate of about 20% for patients diagnosed with distantly metastasized breast cancers. (American Cancer Society statistics). Currently, the best initial indicators of early breast cancer are physical examination of the breast and mammography. J. R. Harris et al. In: Cancer: Principles and Practice of Oncology, Fourth Edition, pp. 1264-1332, Philadelphia, Pa.: J/B. Lippincott Co. (1993). Mammography may detect a breast tumor before it can be detected by physical examination, but it has limitations. For example, mammography""s predictive value depends on the observer""s skill and the quality of the mammogram. In addition, 80 to 93% of suspicious mammograms are false positives, and 10 to 15% of women with breast cancer have false negative mammograms. C. J. Wright et al., Lancet 346:29-32 (1995). New diagnostic methods which are more sensitive and specific for detecting early breast cancer are clearly needed.
Breast cancer patients are closely monitored following initial therapy and during adjuvant therapy to determine response to therapy, and to detect persistent or recurrent disease, or early distant metastasis. Current diagnostic procedures for monitoring breast cancer include mammography, bone scan, chest radiographs, liver function tests and tests for serum markers. The serum tumor markers most commonly used for monitoring patients are carcinoembryonic antigen (CEA) and CA 15-3. Limitations of CEA include absence of elevated serum levels in about 40% of women with metastatic disease. In addition, CEA elevation during adjuvant therapy may not be related to recurrence but to other factors that are not clinically important. CA 15-3 can also be negative in a significant number of patients with progressive disease and, therefore, fail to predict metastasis. Both CEA and CA 15-3 can be elevated in nonmalignant, benign conditions giving rise to false positive results. Therefore, it would be clinically beneficial to find a breast associated marker which is more sensitive and specific in detecting cancer recurrence. J. R. Harris et al., supra. M. K. Schwartz, In: Cancer: Principles and Practice of Oncology Vol. 1, Fourth Edition, pp. 531-542, Philadelphia, Pa.: J/B. Lippincott Co. 1993.
Another important step in managing breast cancer is to determine the stage of the patient""s disease because stage determination has potential prognostic value and provides criteria for designing optimal therapy. Currently, pathological staging of breast cancer is preferable over clinical staging because the former gives a more accurate prognosis. J. R. Harris et at., supra. On the other hand, clinical staging would be preferred were it at least as accurate as pathological staging because it does not depend on an invasive procedure to obtain tissue for pathological evaluation. Staging of breast cancer could be improved by detecting new markers in serum or urine which could differentiate between different stages of invasion. Such markers could be protein markers expressed by cells originating from the primary tumor in the breast but residing in blood, bone marrow or lymph nodes and could serve as sensitive indicators for metastasis to these distal organs. For example, specific protein antigens , associated with breast epithelial cells, have been detected by immunohistochemical techniques, in bone marrow, lymph nodes and blood of breast cancer patients suggesting metastasis. K. Pantel et al., Onkologie 18:394-401 (1995).
Such diagnostic procedures also could include immunological assays based upon the appearance of various disease markers in test samples such as blood, plasma, serum or urine obtained by minimally invasive procedures which are detectable by immunological methods. These diagnostic procedures would provide information to aid the physician in managing the patient with disease of the breast, at low cost to the patient. Markers such as prostate specific antigen (PSA) and human chorionic gonadotropin (hCG) exist and are used clinically for screening patients for prostate cancer and testicular cancer, respectively. For example, PSA normally is secreted by the prostate at high levels into the seminal fluid, but is present in very low levels in the blood of men with normal prostates. Elevated levels of PSA protein in serum are used in the early detection of prostate cancer or disease in asymptomatic men. See, for example, G. E. Hanks et al., In: Cancer: Principles and Practice of Oncology, Vol. 1, Fourth Edition, pp. 1073-1113, Philadelphia, Pa.: J. B. Lippincott Co. 1993. M. K. Schwartz et al., In: Cancer: Principles and Practice of Oncology, Vol. 1, Fourth Edition, pp. 531-542, Philadelphia, Pa.: J. B. Lippincott Co. 1993. Likewise, the management of breast diseases could be improved by the use of new markers normally expressed in the breast but found in elevated amounts in an inappropriate body compartment as a result of the disease of the breast.
Further, new markers which could predict the biologic behavior of early breast cancers would also be of significant value. Early breast cancers that threaten or will threaten the life of the patient are more clinically important than those that do not or will not be a threat. G. E. Hanks, supra. Such markers are needed to predict which patients with histologically negative lymph nodes will experience recurrence of cancer and also to predict which cases of ductal carcinoma in situ will develop into invasive breast carcinoma. More accurate prognostic markers would allow the clinician to accurately identify early cancers localized to the breast which will progress and metastasize if not treated aggressively. Additionally, the absence of a marker for an aggressive cancer in the patient could spare the patient expensive and non-beneficial treatment. J. R. Harris et al., supra. E. R. Frykberg et al., Cancer 74:350-361 (1994).
It therefore would be advantageous to provide specific methods and reagents useful for detecting, diagnosing, staging, monitoring, prognosticating, in vivo imaging, preventing or treating, or determining predisposition to diseases or conditions of the breast. Such methods would include assaying a test sample for products of a gene which are overexpressed in diseases and conditions associated with the breast, including cancer. Such methods may further include assaying a test sample for products of a gene whose distribution among the various tissues and compartments of the body have been altered by a breast-associated disease or condition, including cancer. Such methods would comprise making cDNA from mRNA in the test sample, amplifying, when necessary, portions of the cDNA corresponding to the gene or a fragment thereof, and detecting the cDNA product as an indication of the presence of the disease or condition including cancer or detecting translation products of the mRNAs comprising gene sequences as an indication of the presence of the disease. Useful reagents include polynucleotide(s), or fragment(s) thereof which may be used in diagnostic methods such as reverse transcriptase-polymerase chain reaction (RT-PCR), PCR, or hybridization assays of mRNA extracted from biopsied tissue, blood or other test samples; or proteins which are the translation products of such mRNAs; or antibodies directed against these proteins. Such assays would include methods for assaying a sample for product(s) of the gene and detecting the product(s) as an indication of disease of the breast. For example, these assays would include methods for detecting the gene products (proteins) in light of possible post-translational modifications that can occur in the body. Such post-translational modifications can include proteolytic processing, alteration of the chain termini, glycosylation, lipid attachment, sulfation, gamma-carboxylation, hydroxylation, phosphorylation, ADP-ribosylation, disulfide bond formation, and multiple non-covalent interactions with molecules such as co-factors, inhibitors (both small molecule and protein), activators (both small molecule and protein), and other proteins in formation of multi-subunit complexes. See, for example, T. E. Creighton et al., In: Proteins: Structures and Molecular Properties, Second Edition, pp. 78-102, New York, N.Y.:W. H. Freeman and Co. 1993. Some modifications are sequence specific and are therefore predictive whereas others are not and are observed by empirical data only.
The uteroglobin family of proteins contains a small number of sequences whose function has yet to be identified but may serve in detecting, diagnosing, staging, monitoring, prognosticating, in vivo imaging, preventing or treating, or determining predisposition to diseases or conditions of the breast. L. Miele et al., J Endocrinol. Invest. 17:679-692 (1994). Empirically, uteroglobins have been found to complex with another molecule of themselves, forming a homo-dimeric multi-subunit complex. R. Bally et al., J. Mol Biol 206:153-170(1989); I. Morize et al., J. Mol Biol 194:725-739 (1987); T. C. Umland et al., Nature Structural Biology 1:538-545 (1994); T. C. Umland et al., J. Mol. Biol. 224:441-448(1992). Other sequences that appear to be distantly related to uteroglobins include the rat steroid binding protein and the cat major allergen. Like the uteroglobins, these proteins have been determined to exist as multi-subunit complexes. Unlike uteroglobins, these subunits are heterodimeric, i.e., from different sequences. Furthermore, these heterodimers complex together with either another copy of themselves forming an xcex1xcex2/xcex1xcex2 heterotetramer, as in the cat major allergen [O. A. Duffort et, al., Molecular Immunology 28:301-309 (1991); K. Leitermann et al., J of Allergy and Clinical Immunology 74:147-153 (1991)], or they complex with a different heterodimer, such as the rat steroid binding protein which has the subunit structure xcex1xcex2/xcex1xe2x80x2xcex2 (where xcex1 and xcex1xe2x80x2 are homologous but not identical). M. Parker et al., Nature 298:92-94 (1982). In the case of the cat major allergen, xcex1 is homologous to the uteroglobin family but xcex2 is not. J. P. Morgenstern et al., PNAS 88:9690-9694(1991). In the case of the rat steroid binding protein, xcex1, xcex1xe2x80x2, and xcex2 have varying degrees of homology to the uteroglobin family of proteins.
Mammaglobin has recently been described as a newly discovered addition to the uteroglobin family, albeit a distantly related member. Its expression is reported to be restricted to mammary epithelium by Northern blot and RT/PCR analysis. M. A. Watson et al., Cancer Research 56:860-865 (1996). The gene has been localized to chromosome 11q 13, and several potential transcriptional control elements have been identified. M. A. Watson et al., Oncogene 16:817-824 (1998). Furthermore, the polynucleotide sequence was described in U.S. Pat. 5,668,267. However, there are no reports describing the nature of the protein product.
BU101 was first described as an endometrial specific uteroglobin (WO 97/34997). In contrast, we have recently described BU101 as a breast specific uteroglobin (U.S. Ser. No. 08/697,105 filed on Aug. 19, 1996 which was abandoned in favor of continuation-in-part U.S. Ser. No. 08/912,276 filed on Aug. 15, 1997). Its detection in breast clinical specimens was shown in these previous applications. The nature of Mammaglobin and BU101 protein products is newly described in this application.
Drug treatment or gene therapy for diseases and conditions of the breast including cancer can be based on these identified gene sequences or their expressed proteins, and efficacy of any particular therapy can be monitored. Furthermore, it would be advantageous to have available alternative, non-surgical diagnostic methods capable of detecting early stage breast disease, such as cancer.
All U.S. patents and publications referred to herein are hereby incorporated in their entirety by reference.
The present invention provides a new entity, specifically, a multimeric polypeptide complex or antigen, wherein at least one copy of BU101 polypeptide (SEQUENCE ID NO 6) and at least one copy of Mammaglobin polypeptide (SEQUENCE ID NO 5) are present; however, the complex may also contain one or more unknown polypeptides as well. Such unknown polypeptides have at least 20% identity with the amino acid sequence of the BU101 polypeptide (SEQUENCE ID NO 6), the Mammaglobin polypeptide (SEQUENCE ID NO 5) or fragments thereof. Mammaglobin polypeptide may be present as a glycoprotein, with sugars attached at asparagine residues located at position 53, and/or position 68, or neither. Furthermore, Mammaglobin polypeptide may be linked covalently via disulfide bonds to BU101 polypeptide. Both sequences contain 3 cysteine residues in their mature form. This disulfide-linked heterodimer may constitute one subunit of the complex; it may have interactions with another subunit of identical composition, forming an xcex1xcex2/xcex1xcex2 heterotetramer; or it may interact with a subunit of nonidentical composition, forming an xcex1xcex2/xcex1xe2x80x2xcex2, or an xcex1xcex2/xcex1xcex2xe2x80x2, or an xcex1xcex2/xcex1xe2x80x2xcex2xe2x80x2 heterotetramer, where xcex1 represents BU101 polypeptide, xcex2 represents Mammaglobin polypeptide, xcex1xe2x80x2 represents a polypeptide homologous to but not identical to BU101 polypeptide, and xcex2xe2x80x2 represents a polypeptide homologous to but not identical to Mammaglobin polypeptide. The gene encoding the BU101 polypeptide may contain a single base T/C polymorphism which results in either a proline residue (encoded by CCG) or a leucine residue (encoded by CTG) at amino acid 53 of the polypeptide. The multimeric polypeptide complex can be produced by recombinant technology, produced by isolation from natural sources, or produced by synthetic techniques.
A method for producing a polypeptide, or polypeptide complex, which contains at least one epitope of a multimeric polypeptide complex is provided, which method comprises incubating host cells transfected with one or more expression vector(s). The vector(s) comprises a polynucleotide sequence encoding one or more polypeptide(s), wherein the polypeptide(s) comprises an amino acid sequence having at least 20% identity with an amino acid sequence selected from the group consisting of BU101 polypeptide (SEQUENCE ID NO 6), Mammaglobin polypeptide (SEQUENCE ID NO 5), or an unknown xcex1xe2x80x2 or xcex2xe2x80x2 polypeptide, and fragments thereof.
The present invention provides a cell co-transfected with nucleic acid sequences that encode at least one component polypeptide sequence of a multimeric polypeptide antigen, or fragments thereof. The nucleic acid sequence is selected from the group consisting of BU101 (SEQUENCE ID NO 2), Mammaglobin (SEQUENCE ID NO 1), xcex1xe2x80x2, or xcex2xe2x80x2, and fragments or complements thereof.
A method for producing antibodies to antigens consisting of either BU101 polypeptide (SEQUENCE ID NO 6), Mammaglobin polypeptide (SEQUENCE ID NO 5), unknown xcex1xe2x80x2 or xcex2xe2x80x2 polypeptide, or a multimeric polypeptide complex, or fragments thereof, also is provided, which method comprises administering to an individual an isolated immunogenic polypeptide, polypeptide complex, or fragment thereof, wherein the isolated immunogenic polypeptide comprises at least one epitope of the multimeric polypeptide complex. The immunogenic polypeptide, polypeptide complex, or fragment thereof is administered in an amount sufficient to produce an immune response. The isolated, immunogenic polypeptide, polypeptide complex, or fragment thereof comprises an amino acid sequence selected from the group consisting of BU101 polypeptide (SEQUENCE ID NO 6), Mammaglobin polypeptide (SEQUENCE ID NO 5), unknown xcex1xe2x80x2 or xcex2xe2x80x2 polypeptide sequence, and fragments thereof. The antibody may be monoclonal or polyclonal.
Also provided is an antibody which specifically binds to at least one epitope of the multimeric polypeptide complex. The antibody does not bind to any of the isolated polypeptide chains of the complex. The antibody can be a polyclonal or monoclonal antibody. The epitope is derived from an amino acid sequence having at least 20% identity to an amino acid sequence selected from the group consisting of BU101 polypeptide (SEQUENCE ID NO 6), Mammaglobin polypeptide (SEQUENCE ID NO 5), unknown xcex1xe2x80x2 or xcex2xe2x80x2 polypeptides, fragments thereof, or any combination thereof. That is, the epitope may be shared between polypeptide sequences.
Also provided is an antibody which specifically binds to at least one epitope of the BU101 polypeptide (SEQUENCE ID NO 6). The antibody may or may not bind to the multimeric polypeptide complex. The antibody can be a polyclonal or monoclonal antibody. The epitope is derived from an amino acid sequence selected from the group consisting of BU101 polypeptide (SEQUENCE ID NO 6), and fragments thereof.
Also provided is an antibody which specifically binds to at least one epitope of the Mammaglobin polypeptide (SEQUENCE ID NO 5). The antibody may or may not bind to the multimeric polypeptide complex. The antibody can be a polyclonal or monoclonal antibody. The epitope is derived from an amino acid sequence selected from the group consisting of Mammaglobin polypeptide (SEQUENCE ID NO 5), and fragments thereof.
Also provided is an antibody which specifically binds to at least one epitope of an unknown xcex1xe2x80x2 polypeptide. The antibody may or may not bind to the multimeric polypeptide complex. The antibody can be a polyclonal or monoclonal antibody.
Also provided is an antibody which specifically binds to at least one epitope of an unknown xcex2xe2x80x2 polypeptide. The antibody may or may not bind to the multimeric polypeptide complex. The antibody can be a polyclonal or monoclonal antibody.
A method for detecting the multimeric polypeptide antigen in a test sample suspected of containing the multimeric polypeptide antigen also is provided. The method comprises contacting the test sample with an antibody or fragment thereof which specifically binds to at least one epitope of the multimeric polypeptide antigen, for a time and under conditions sufficient for the formation of antibody/antigen complexes; and detecting the presence of such complexes containing the antibody as an indication of the presence of the multimeric polypeptide antigen in the test sample. The antibody can be attached to a solid phase and may be either a monoclonal or polyclonal antibody. Again, the antigen to be detected may contain at least one BU101 polypeptide and at least one Mammaglobin polypeptide. It may contain, in addition, at least one polypeptide having at least 20% identity with an amino acid sequence selected from the group consisting of SEQUENCE ID NO;5, SEQUENCE ID NO:6, and fragments thereof.
Assay kits for determining the presence of the multimeric polypeptide antigen in a test sample are also included. In one embodiment, the assay kit comprises a container containing an antibody which specifically binds to a multimeric polypeptide antigen, wherein the antigen comprises at least one epitope encoded by either the BU101 gene, the Mammaglobin gene, the xcex1xe2x80x2 gene, or the xcex2xe2x80x2 gene. These test kits can further comprise containers with tools useful for collecting test samples (such as blood, urine, saliva, and stool). Such tools include lancets and absorbent paper or cloth for collecting and stabilizing blood; swabs for collecting and stabilizing saliva; cups for collecting and stabilizing urine or stool samples. Collection materials, such as papers, cloths, swabs, cups and the like, may optionally be treated to avoid denaturation or irreversible adsorption of the sample. These collection materials also may be treated with, or contain, preservatives, stabilizers or antimicrobial agents to help maintain the integrity of the specimens. The antibody can be attached to a solid phase.
Another method is provided which detects antibodies which specifically bind to the multimeric polypeptide antigen in a test sample suspected of containing these antibodies. The method comprises contacting the test sample with a polypeptide which contains at least one epitope of the multimeric polypeptide complex. Contacting is performed for a time and under conditions sufficient to allow antigen/antibody complexes to form. The method further entails detecting complexes which contain the polypeptide. The polypeptide complex can be attached to a solid phase. Further, the polypeptide complex can be produced recombinantly, or synthetically, or purified from natural sources. The multimeric polypeptide antigen may comprise at least one BU101 polypeptide, at least one Mammaglobin polypeptide, or fragments thereof. It may further comprise at least one polypeptide having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof.
Assay kits for determining the presence of anti-multimeric polypeptide complex antibody in a test sample are also included. In one embodiment, the assay kits comprise a container containing at least one polypeptide of the multimeric polypeptide complex. Further, the test kit can comprise a container with tools useful for collecting test samples (such as blood, urine, saliva, and stool). Such tools include lancets and absorbent paper or cloth for collecting and stabilizing blood; swabs for collecting and stabilizing saliva; and cups for collecting and stabilizing urine or stool samples. Collection materials such as papers, cloths, swabs, cups, and the like, may optionally be treated to avoid denaturation or irreversible adsorption of the sample. These collection materials also may be treated with or contain preservatives, stabilizers or antimicrobial agents to help maintain the integrity of the specimens. Also, the polypeptide can be attached to a solid phase.
In another embodiment of the invention, antibodies or fragments thereof, against the multimeric polypeptide antigen can be used to detect or image localization of the antigen in a patient for the purpose of detecting or diagnosing a disease or condition. Such antibodies can be polyclonal or monoclonal, or made by molecular biology techniques, and can be labeled with a variety of detectable labels, including but not limited to, radioisotopes and paramagnetic metals. Furthermore, antibodies or fragments thereof, whether monoclonal, polyclonal, or made by molecular biology techniques, can be used as therapeutic agents for the treatment of diseases characterized by expression of the multimeric polypeptide antigen. In the case of therapeutic applications, the antibody may be used without derivitization, or it may be derivitized with a cytotoxic agent such as a radioisotope, enzyme, toxin, drug, prodrug, or the like.
Additionally, the present invention encompasses a method of detecting the presence of a multimeric polypeptide antigen (MPA) in a test sample suspected of containing said MPA, wherein the MPA comprises at least one BU101 polypeptide and at least one Mammaglobin polypeptide. This method comprises the steps of: a) contacting the test sample with at least one antibody specific for at least one epitope of the MPA for a time and under conditions sufficient to allow the formation of MPA/antibody complexes; (b) adding a conjugate to the resulting MPA/antibody complexes for a time and under conditions sufficient to allow the conjugate to bind to the bound antigen, wherein the conjugate comprises an antibody attached to a signal generating compound capable of generating a detectable signal; and (c) detecting the presence of MPA which may be present in the test sample by detecting the signal generated by said signal generating compound. The multimeric polypeptide antigen may further comprise at least one polypeptide having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof.
Furthermore, the present invention also includes a method of detecting the presence of antibody specific for a multimeric polypeptide antigen (MPA) in a test sample suspected of containing the antibody, wherein the MPA comprises at least one BU101 polypeptide and at least one Mammaglobin polypeptide. The method comprises the steps of: (a) contacting the test sample with at least one epitope of MPA derived from an amino acid sequence or fragment thereof having at least 20% identity to an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof, for a time and under conditions sufficient to allow the formation of MPA/antibody complexes; (b) adding a conjugate to the resulting MPA/antibody complexes for a time and under conditions sufficient to allow the conjugate to bind to the bound antigen, wherein the conjugate comprises an antibody attached to a signal generating compound capable of generating a detectable signal; and (c) detecting the presence of the antigen which may be present in the test sample by detecting the signal generated by the signal generating compound. The multimeric polypeptide antigen may further comprise at least one polypeptide having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof.
Moreover, the present invention includes an assay kit for determining the presence of a multimeric polypeptide antigen (MPA) or anti-MPA antibody in a test sample suspecting of containing the MPA antigen or anti-MPA antibody. The assay kit comprises a container containing a MPA polypeptide having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof. The MPA polypeptide may be attached to a solid phase.
In addition, the present invention includes an assay kit for determining the presence of a multimeric polypeptide antigen (MPA), in a test sample suspected of containing the antigen, comprising a container containing an antibody which specifically binds to at least one epitope of MPA, the epitope comprising an amino acid sequence having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof.
Also, the present invention encompasses a composition of matter comprising a multimeric polypeptide antigen, wherein the antigen comprises at least one BU101 polypeptide and at least one Mammaglobin polypeptide. The antigen may further comprise at least one polypeptide having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof. The antigen may be bound to at least one antibody specific to at least one polypeptide selected from the group consisting of a BU101 polypeptide, a Mammaglobin polypeptide, one polypeptide having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, fragments thereof, and a combination thereof. Two antibodies may be present such that each binds to a separate polypeptide having an amino acid sequence having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof. Alternatively, each of the two antibodies may bind to a BU101 polypeptide or a fragment thereof. Also, each of the two antibodies may bind to a Mammaglobin polypeptide or a fragment thereof, or one of the two antibodies may bind to a BU101 polypeptide or a fragment thereof and the other of the two antibodies may bind to a Mammaglobin polypeptide or fragment thereof. Another possibility is that one of the two antibodies may bind to a BU101 polypeptide or fragment thereof and the other of the two antibodies may bind to a polypeptide having an amino acid sequence having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof. Alternatively, one of the two antibodies may bind to a Mammaglobin polypeptide or fragment thereof and the other of the two antibodies may bind to a polypeptide having an amino acid sequence having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof.
Furthermore, the present invention also includes a method of detecting breast cancer in a patient suspected of having breast cancer comprising the steps of: (a) administering to the patient a labelled antibody specific to a multimeric protein antigen (MPA), wherein the MPA comprises at least one BU101 polypeptide and at least one Mammaglobin polypeptide; and (b) localizing presence of the label, presence of the label indicating presence of MPA and breast cancer in the patient. The MPA may further comprise at least one polypeptide having at least 20% identity with an amino acid sequence elected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof.
The present invention also includes a method of treating breast cancer in a patient comprising administering to the patient an antibody specific to a multimeric polypeptide antigen (MPA). The MPA comprises at least one BU101 polypeptide and at least one Mammaglobin polypeptide. The multimeric polypeptide antigen may further comprise at least one polypeptide having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof.
Also, the present invention includes a method of diagnosing breast cancer in a patient suspecting of having breast cancer comprising the steps of: (a) preparing a tissue section or cell culture derived from a tumor excised from the patient; (b) exposing the tissue section or cell culture to an antibody specific for at least one polypeptide of a multimeric polypeptide antigen (MPA) for a time and under conditions sufficient to allow formation of antigen/antibody complexes, the polypeptide being selected from the group consisting of: a BU101 polypeptide, a Mammaglobin polypeptide, a polypeptide having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof; (c) localizing presence of the complexes in the tissue section or cell culture, presence of the complexes indicating presence of MPA and breast cancer in the patient.
Also, the present invention encompasses a method of diagnosing or detecting breast cancer in a patient suspected of having breast cancer comprising the steps of: detecting the presence or absence of at least one polypeptide of a multimeric polypeptide antigen (MPA), the polypeptide being selected from the group consisting of a BU101 polypeptide, a Mammaglobin polypeptide, and a polypeptide having at least 20% identity with an amino acid sequence elected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof, in a biological sample from the patient, presence of the at least one polypeptide indicating presence of MPA and breast cancer in the patient. The biological sample may be selected from the group consisting of, for example, urine, bone marrow and blood.
Additionally, the present invention includes a method of diagnosing breast cancer in a patient suspected of having breast cancer comprising the steps of detecting the presence or absence of extracellular BU101 in said patient, presence of extracellular BU101 indicating breast cancer in the patient and transport of BU101 outside cells via Mammaglobin in a multimeric polypeptide antigen (MPA). The MPA comprises at least one BU101 polypeptide and at least one Mammaglobin polypeptide. The MPA may further comprise at least one polypeptide having at least 20% identity with an amino acid sequence selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, and fragments thereof.
Furthermore, the present invention encompasses a method of detecting breast cancer in a patient suspected of having breast cancer comprising the steps of: (a) obtaining a biological sample from the patient; (b) measuring the amount of free BU101 polypeptide in the biological sample; (c) measuring the amount of BU101 polypeptide, present in the biological sample, complexed to Mammaglobin polypeptide; and (d) comparing the ratio of free BU101 polypeptide to complexed BU101 polypeptide, a ratio higher than 1 indicating presence of breast cancer in the patient.
Additionally, the present invention includes a method of detecting breast cancer in a patient suspecting of having breast cancer comprising the steps of: (a) measuring the amount of free Mammaglobin polypeptide in a biological sample from the patient; (b) measuring the amount of Mammaglobin polypeptide, present in said biological sample, complexed to BU101 polypeptide; and (c) comparing the ratio of free Mammaglobin polypeptide to complexed Mammaglobin polypeptide, a ratio higher than 1 indicating presence of breast cancer in the patient.